Currently, lighting apparatuses using organic light-emitting diodes as a luminescent source have occupied a large proportion in the consumer market. The lighting apparatuses using the organic light-emitting diodes as the luminescent source are advantageous for having a fabrication material not containing mercury, and capable of providing an illumination source without UV light. In comparison with lighting apparatuses using light-emitting diodes as an illumination source, a less-preferable uniformity of color light may be provided since the light-emitting diode is a spot light source incapable of providing an illumination source with a color temperature approximate to nature light. The organic light-emitting diode is a plane light source with a preferable uniformity of color light and suitable for illumination of nature light. On the other hand, because a brightness of the organic light-emitting diode is proportional to a driving current flowing through the organic light-emitting diode itself, changes in the driving current may also lead to variations in the color temperature of the illumination source. Accordingly, how to adjust the color temperature of the illumination source is important in the case where the brightness of the organic light-emitting diode must remain unchanged.